I am using Recurrent Complex in the light mode or whatever it's called. I pre-gen'd the world and everything has been fine for about two months, but starting yesterday, I've been getting multiple crashes pointing to this mod as the problem. I disabled the mod and everything was fine, I then re-enabled it and the server is crashing again. Here are some of the crash reports I've gotten:

https://pastebin.com/G1q1vNpd
https://pastebin.com/hkmP8uw6 (most are like this)

Try updating to 1.10.

I had the same problem, used Verson 1.2.4 of the mod and it worked. ;D

Closing stale issue.